Substituted phenylalkyl compounds

ABSTRACT

Novel antibacterially-active compound, 1,2,8,8a-cyclopropa[c]benzo[1,2-b:-4,3-b&#39;]dipyrol-4(5H)-one, prepared by a novel chemical process. This compound, as well as antibacterially-active intermediates, can be used to eradicate or control susceptible bacteria, for example, B. subtilis, K. pneumonia, S. lutea, S. aureus, and M. avium.

This is a continuation-in-part of application Ser. No. 346,642, filedFeb. 8, 1982, now abandoned, which is a division of application Ser. No.207,838, filed Nov. 18, 1980, now abandoned.

DESCRIPTION BACKGROUND OF THE INVENTION

Antibiotic CC-1065, is disclosed and claimed by its chemical andphysical parameters in U.S. Pat. No. 424,121. Subsequently, thestructure of antibiotic CC-1065 was elucidated as disclosed in"Structure Proof of Antibiotic CC-1065", D. G. Martin, C. G. Chidester,D. J. Duchamp, and S. A. Mizsak, J. Antibiot., 33 902 (1980). Thestructure of antibiotic CC-1065 is shown in CHART 1. Antibiotic CC-1065consists of a 3-fragment system with the most labile portion of themolecule being the fragment named1,2,8,8a-cyclopropa[c]benzo[1,2-b:4,3-b']dipyrol-4(5H)-one, which isdenoted herein as compound (12). Attempts to obtain this fragment bydegradation of antibiotic CC-1065 have failed. Thus, there is no knownprior art method to obtain compound (12).

BRIEF SUMMARY OF THE INVENTION

Compound (12) of the subject invention can be made by an 11-step processdisclosed in CHART 2. This compound, as well as certain intermediatesdisclosed herein, are active against certain bacteria, for example,Bacillus subtilis, Klebsiella pneumonia, Sarcina lutea, Staphylococcusaureus, and Mycobacterium avium. Accordingly, these compounds can beused to disinfect washed and stacked food utensils contaminated with S.aureus. Further, the antibacterially-active compounds of this inventioncan be used as bacteriostatic rinses for laundered clothes, and forimpregnating papers and fabrics; and, they are also useful forsuppressing the growth of sensitive organisms in plate assays andmicrobiological media. In general, the antibacterially-active compoundsof this invention can be used in the same manner as disclosed forantibiotic CC-1065 in U.S. Pat. No. 4,169,888. These uses are well-knownin the antibiotic art. Accordingly, bacteriological techniques arereadily available to persons skilled in this art to practice such uses.

DETAILED DESCRIPTION OF THE INVENTION

As disclosed above the 11-step process for preparing compound (12) isshown in Chart 2. These steps are as follows:

Step 1--The first step (aromatic nucleophilic substitution) in thesynthetic approach is described by J. Bourdais and C. Mahieu, Compt.Redux [C], 263, 84 (1966). Also see J. Bourdais and C. Germain, Tet.Letters, 195 (1970). The various R₁ groups can be introduced on thephenol precursor of (1) by procedures described in the literature(appropriate references detailed under step 8). The various malonates,β-keto esters, and β-diketones employed are all known compounds.

Step 2--Reduction. When R₃ =alkoxy, diisobutylaluminum hydride is thereagent of choice. Reaction conditions are quite specific (seeExample 1) for optimum yields. When R₃ =alkyl or phenyl, standardreduction procedures employing sodium borohydride can be employed.

Step 3--Functional group interchange. The chemistry describedspecifically herein is in the case of X=OSO₂ CH₃. The mesylate ortosylate (for example) can be prepared under standard conditions knownin the art employing pyridine (with or without solvent, such asmethylene chloride) or other acid acceptors such as trialkylamines (withsolvent) and the corresponding sulfonyl chloride. The halogen analogs of4 can be prepared under standard procedures known in the art such as Ph₃P/CCl₄ (CBr₄) and N-iodosuccinimide/triphenylphosphine.

Step 4--Reduction-cyclization. This step is a novel preparation ofindolines (dihydroindoles). This involves the reduction of the nitro tothe amino group with concomitant intramolecular cyclization to give (5).The reduction step described in detail herein utilizes H₂, PtO₂ inalcohol in the presence of a tertiary amine. These are standardhydrogenation conditions in the art. Palladium or nickel catalysts canalso be employed and bases other than a tertiary amine, such aspyridine, can be utilized. Alternate reducing conditions can employ Feor TiCl₃ in acid or SnCl₂. This may then require a separate stepinvolving treatment with base to induce the cyclization to (5). Anexample of a reduction with iron is the use of Fe/CH₃ CO₂ H/CH₃ CH₂ OH(G. S. Ponticello and J. J. Baldwin, J. Org. Chem., 44, 4003 (1979).These conditions would be required if R₁ =CH₂ Ph or --CH₂ CH═CH₂.

The concept of nitro reduction followed by in situ cyclization toindoles is advanced by A. D. Batcho and W. Leimgruber, German Offen.2057840 (1971), which is a significant improvement over the olderReissert procedure of reductive cyclization to indoles. (See R. J.Sundberg, The Chemistry of Indoles, pp. 176-183. Academic Press, N.Y.,1970).

Step 5--Substitution of labile group. This step is required due to theincompatibility of X with the chemistry of step 8. It involves thereplacement of X with an acetate or the conjugate base of a C₁ -C₅ alkylcarboxylic acid under standard conditions (alkali carboxylate inacetone, DMF, or alcohol). Since some hydrolysis can occur when X=OSO₂CH₃, the reaction mixture is treated with acetic anhydride prior toisolation of (6).

Step 6--Nitration can be performed under a variety of conditionsdescribed in the literature including nitric acid in acetic acid, aceticanhydride, sulfuric acid, acetic acid/H₂ O, alcohol, and nitroalkanes.The regioselectivity of this reaction is supported by the spectroscopicdata obtained.

Step 7--Reduction of the nitro to the amino group follows the samechemical description given in step 4 with the omission of base.

Step 8--Indole synthesis. This procedure is based generally on theindole chemistry of Gassman [P. G. Gassman, et. al., J. Am. Chem. Soc.,96, 5494, 5508, 5512 (1974)]. Several modifications are required whichare not disclosed or suggested in Gassman's work. The sequence of thechemical events and some of the intermediates are depicted in CHART 3.The α-thiomethyl esters are known.

This process deviates from the published Gassman route by employing thechlorosulfonium complex, A, and reacting it with the aniline, (6);Gassman prepares the chloroamine of an aniline and reacts it with thethioether in making oxindoles. Secondly, two different bases areemployed in the process, whereas Gassman uses two equivalents of theaniline followed by a base₂. Although triethylamine,diisopropylethylamine, bis(1,8-dimethyl amino)naphthalene, and the likeboth work for base₁ and base₂, the preferred for base₁ isbis(1,8-dimethylamine)napthalene, and triethylamine for base₂. Differentsolvents such as chloroform, acetonitrile, tetrahydrofuran (THF), andmethylene chloride can be used, the latter is preferred. The temperaturerange if from -50° to -80° and the reaction is run under an inertatmosphere. The cyclization to the oxindole B is best promoted by acidcatalysis as described by Gassman (2N HCl, ether and/or ethyl acetate).

The final reduction to (9) (reductive elimination) can be accomplishedwith lithium aluminum hydride (as described by Gassman) or diborane typereagents, the latter being far superior. The preferred reagent is (CH₃)₂S.BH₃ in THF at room temperature for 24 hours.

Step 9--This deprotection step (removal of R₁) is described in detailfor R₁ =CH₃ in Example 8. Although there are a number of proceduresdescribed in the art involving methyl ether cleavage, only alkylmercaptide in hexamethylphosphorictriamide (HMPA) under an inertatmosphere (95°-110°) have been found to be effective [S. C. Welch andA. S. C. P. Rao, Tet. Letters, 505 (1977) and T. R. Kelly, H. M. Dali,and W-G. Tsang, Tet. Letters, 3859 (1977), or Me₂ S.BBr₃ indichloroethane (P. G. Willard and C. B. Fryhle, Tet. Letters, 3731(1980)].

When R₁ =CH₂ Ph, standard hydrogenolysis conditions suffice to deprotect(H₂, Pd/C) [Org. Reactions, 7, 263 (1953)]. When R₁ =CH₂ SCH₃, mercuricchloride in acetonitrile/H₂ O removes the ether (R. A. Holton and R. G.Davis, Tet. Letters, 533 (1977). When R₁ =CH₂ OCH₃, moderate acid willgenerate the phenol-10, such as acetic acid [J. Med. Chem., 9, 1 (1966)or Synthesis, 244 (1976)]. In fact, this protecting group may be lost instep 6, however, it can be reintroduced prior to step 7 under standardconditions. When R₁ =--CH₂ OCH₂ CH₂ OCH₃, the phenol can be generated byZnBr₂ or TiCl₄ in CH₂ Cl₂ [Tet. Letters, 809 (1976)]. When R₁ =--CH₂CH═CH₂, several two-step procedures will deprotect the ether (Pd/C inalcohol/Ang. Chem. Int. Ed., 15, 558 (1976); SeO₂, CH₃ CO₂ H indioxane/Tet. Letters, 2885 (1970); t-BuOK, DMSO followed by H₂ SO₄ inacetone/J. Chem. Soc., 1903 (1965); RhCl(PPh₃)₃, DABCO in alcoholfollowed by pH2 [J. Org. Chem., 38, 3224 (1973)]. When R₁ =--CH₂ CH₂Si(R₂)₃ deprotection is effected by Bu₄ NF [H. Gerlach, et. al., Helv.Chim. Acta, 60, 3039 (1977)].

Step 10--See step 3.

Step 11--This step (when X=Br) is promoted by contact with silica gel aswell as occurs on standing in protic solvents. This reaction will alsoproceed in the presence of such bases as tertiary amines, pyridine,t-butoxide, and the like and weak aqueous bases such as bicarbonate andcarbonate.

The following examples are illustrative of the products and process ofthe invention, but are not to be construed as limiting. All percentagesare by weight and all solvent mixture proportions are by volume unlessotherwise noted.

EXAMPLE 1 Preparation of the 2-aryl-1,3-propandiol (3) from thearyldiethylmalonate (2)

To 400 ml of THF under N₂ cooled in an ice-water bath is added 100 g ofDIBAL* (0.70 mole) in 400 ml of toluene. To this stirred solution isadded 33.0 g (0.105 mole) of the arylmalonate (2) in 100 ml of THF. Therate of addition is controlled to keep the reaction temperature below5°. After the addition is complete the ice bath is removed. The reactionis quenched after 3 hours total reaction time by the portion-wiseaddition of the solution to cold 3N HCl with stirring (approximately 1.5l). The mixture is then extracted with 1 l of EtOAc followed by 1000 mlCH₂ Cl₂. The combined organic phases are dried over Na₂ SO₄ andconcentrated to a red-brown residue (21.2 g). Chromatography of theresidue on 500 g silica gel with 60% EtOAc/hexane→100% EtOAc gradienteluent affords 11.7 g (49% yield ) of the diol (3) (U-62,598) as a lightred oil (solidifies on standing in the freezer).

NMR (CDCl₃): 7.5-7.0 (m, 3H), 3.80 (s, 3H), 4.0-3.3 (m, 7H includes 2OH).

MS: Calc. for C₁₀ H₁₃ NO₅ : 227.0794, Found: 227.0780.

Analysis: Calc: C, 52.86, H, 5.76, N, 6.16; Found: C, 53.40, H, 5.77, N,5.99.

EXAMPLE 2 Preparation of the 2-aryl-1,3-propandiol bismesylate (4) fromthe 2-aryl-1,3-propandiol (3)

To 4.7 g (0.2 moles) of the diol (3) in 100 ml of dry pyridine under N₂at 0°-5° is added with stirring 6.8 g (0.06 mole) of methanesulfonylchloride. After stirring at 5° for 30 minutes followed by roomtemperature for 90 minutes, the solution is concentrated in vacuo, thentaken up in CH₂ Cl₂ /1N HCl. The organic phase is separated, dried overNa₂ SO₄, concentrated to a residue. Trituration with EtOAc affords anoff-white solid and the mother liquors can be chromatographed on silicagel (EtOAc eluent) to afford a total yield of 6.65 g (86% yield), m.p.122°-3° (recrystallized from acetone) of compound (4), bismesylate(U-62,597).

NMR (Acet-d₆): 7.7-7.2 (m, 3H), 4.62 (d, 4H, J=J Hz), 4.11 (t, 1H, J=7Hz), 3.92 (s, 3H), 3.06 (s, 6H).

Analysis: Calc for C₁₂ H₁₇ NO₉ S₂ : Calc: C, 37.59, H, 4.47, N, 3.65;Found: C, 37.35, H, 4.44, N, 3.59.

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₉₀ (μg/ml)=6.0, ID₉₀ (μg/ml)=18

EXAMPLE 3 Preparation of the 6-methoxyindoline bismesylate (5) from the2-aryl-1,3-propandiol bismesylate (4)

To 1.91 g (0.005 mole) of compound (4) in 30 ml of THF, 20 ml of EtOAc,and 150 ml of absolute ethanol is added 1.5 ml of triethylamine and 400mg of PtO₂. This solution is placed under 7-10 psi H₂ pressure withshaking for 30 minutes. The reaction solution is then filtrated overcelite and concentrated in vacuo. After several CH₂ Cl₂ azeotropes invacuo, the residue is ultimately taken up in 100 ml of CH₂ Cl₂ andcooled under N₂ in an ice bath. To the stirred solution is added 1.5 mlof triethylamine followed by the dropwise addition of 900 μl methanesulfonylchloride. After stirring for 30 minutes, the solution is allowedto come to room temperature for 60 minutes. The solution is then washedwith 1N HCl, dried over Na₂ SO₄, and concentrated. The residue israpidly chromatographed on 150 g silica gel with 500 ml of 60%EtOAc/hexane followed by 1000 ml of 80% elution; recovered 1.3 g (78%yield) of an off-white solid, m.p. 122°-3° (recrystallized from ethanol)of compound (5), the 6-methoxyindoline bismesylate (U-62,586).

NMR (DMF-d₇): 7.36 (d, 1H, J=8.5 Hz), 7.00 (d, 1H, J=2 Hz), 6.69 (dd,1H, J=2, 8.5 Hz), 4.47 (2H, d, J=6 Hz), 4.3-3.6 (m, 3H), 3.80 (s, 3H),3.20 (s, 3H), 3.07 (s, 3H).

Analysis: Calc for C₁₂ H₁₇ NS₂ O₆ : Calc: C, 42.97, H, 5.11, N, 4.18;Found: C, 42.87, H, 5.27, N, 4.29.

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=4.8, ID₉₀ (μg/ml)=10

EXAMPLE 4 Preparation of the 6-methoxy indoline acetate (6) from the6-methoxy indoline bismesylate (5)

To 13.0 g (39 mmol) of the 6-methoxy indoline bismesylate (5) in 30 mlof DMF is added 800 ml of abs. ethanol followed by 32 g of sodiumacetate. This hereogeneous solution is refluxed under N₂ for 24 hours,cooled, and concentrated in vacuo. The residue is treated with 100 ml ofacetic anhydride for 2 hours (stirring at room temperature), thenconcentrated in vacuo. The residue is taken up in CH₂ Cl₂ /H₂ O and theorganic phase is separated, dried over Na₂ SO₄, filtered throughcharcoal, and concentrated to an oil which solidifies; 11.6 g ofcompound (6), the 6-methoxy indoline acetate (100%; if necessary,further purification is possible with silica gel chromatographyemploying 60% EtOAc/hexane eluent).

NMR (CDCl₃): 7.17 (d, 1H, J=8.5 Hz), 7.02 (d, 1H, J=2 Hz), 6.60 (dd, 1H,J=2, 8.5 Hz), 4.18 (d, 2H, J=6 Hz), 4.1-3.4 (m, 3H), 3.78 (s, 3H), 2.91(s, 3H), 2.05 (s, 3H).

Analysis: Calc for C₁₃ H₁₇ NO₅ S: Calc: C, 52.16, H, 5.76, N, 4.68;Found: C, 52.13, H, 5.79, N, 5.27.

MS: Calc: 299.0827; Found: 299.0823.

EXAMPLE 5 Preparation of the 5-nitro-6-methoxy indoline acetate (7) fromthe 6-methoxy indoline acetate (6)

To 500 mg (1.67 mmole) of the 6-methoxy indoline acetate (6) in 20 ml ofnitromethane is added 90 μl of 90% HNO₃. The cooled reaction solution(0°-5°) is stirred for 30 minutes, then warmed to room temperature for30 minutes. The solution is diluted with CH₂ Cl₂ and aqueous sodiumbicarbonate. The organic phase is separated, dried over Na₂ SO₄, andconcentrated. The residue is chromatographed on 50 g silica gel (60%EtOAc/hexane eluent→100% EtOAc) yield; 440 mg (76% yield) of a yellowsolid, m.p. 175°-7° (recrystallized from ethanol) of compound (7), the5-nitro-6-methoxy indoline acetate (U-62,696).

NMR (DMF-d₇): 7.91 (s, 1H), 7.20 (s, 1H), 4.27 (d, 2H, J=6 Hz), 4.3-3.7(m, 3H), 3.98 (s, 3H), 3.17 (s, 3H), 2.07 (s, 3H).

Analysis: Calc for C₁₃ H₁₆ N₂ O₇ S: Calc: C, 45.34, H, 4.68, N, 8.14;Found: C, 44.81, H, 4.77, N, 8.16.

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=>50, ID₉₀ (μg/ml)=>50

EXAMPLE 6 Preparation of the 5-amino-6-methoxy indoline acetate (8) fromthe 5-nitro-6-methoxy indoline acetate (7)

To 4.5 g (13 mmole) of the 5-nitro-6-methoxy indoline acetate (7) in 50ml of THF and 150 ml of absolute ethanol is added 500 mg PtO₂ and shakenunder 10 psi of H₂ until uptake ceases (approximately 60 minutes).Filter and concentrate in vacuo. Upon concentration, 3.0 g of productprecipitates out. This is filtered off and the mother liquors rapidlychromatographed on 100 g silica gel with EtOAc eluent to afford anadditional 0.6 g. The total yield (3.6 g) is 88%; m.p. 134°-5° (fromacetone/cyclohexane) of compound (8), the 5-amino-6-methoxy indolineacetate (U-62,697).

NMR (CDCl₃): 7.02 (s, 1H), 6.65 (s, 1H), 4.16 (d, 2H, J=6 Hz), 4.1-3.5(m, 3H), 3.83 (s, 3H), 3.6 (br. s, 2H), 2.83 (s, 3H).

Analysis: Calc for C₁₃ H₁₈ N₂ O₅ S: Calc: C, 49.67, H, 5.77, N, 8.91;Found: C, 49.74, H, 5.72, H, 8.94.

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=>50, ID₉₀ (μg/ml)=>50

EXAMPLE 7 Preparation of the 4,5-pyrrolo-6-methoxy indoline (9) from the5-amino-6-methoxy indoline acetate (8)

To 14 ml of dry CH₂ Cl₂ under N₂ at -75° is added 6.0 ml of a Cl₂ /CH₂Cl₂ solution (20 μl Cl₂ /ml CH₂ Cl₂). To this stirred solution is added370 μl (2.5 mmole) of CH₃ (CH₃ S)CHCO₂ C₂ H₅ (prepared from CH₃(Br)CHCO₂ C₂ H₅ and methyl mercaptide by the procedure of E. H. Wick, T.Yamanishi, H. C. Wertheimer, Y. E. Hoff, B. F. Proctor, and S. A.Goldblith, J. Agr. Food Chem., 9, 289 (1961)). After 5 minutes asolution of 470 mg (2.2 mmole) of 1,8-bisdimethylaminonapthalene and 628mg (2.0 mmole) of the anilinoindoline (8) in 3.0 ml of dry CH₂ Cl₂ isadded dropwise over 15 minutes. The red solution is stirred for 2 hoursat -75°, then 350 μl of triethylamine in 650 μl of CH₂ Cl₂ is addeddropwise over several minutes. The cooling bath is removed. When thereaction solution reaches room temperature it is briefly concentrated invacuo. To the residue is added 5 ml EtOAc, 25 ml of ether and 6 ml of 2NHCl and stirred vigorously for 2 hours. The organic phase is separatedand the aqueous is extracted with 1:1 EtOAc/Et₂ O. The organics arecombined, dried over Na₂ SO₄ and concentrated. At this point the residueis taken up in 10 ml of THF and treated with 3.0 ml of 2M BH₃.SMe₂overnight at room temperature under N₂. Alternatively the diastereomericoxindoles (B) derived from the acid treatment can be isolated at thispoint by silica gel chromatography (50 g; 60% EtOAc/hexane to 90%EtOAc/hexane).

GS-MS: m/e M⁺ 414 (15%), 227 (100%)-2' 1% SE-30.

NMR(CDCl₃): 8.4 (br. s, 1H), 7.11 (s, 1H), 4.5-3.7 (m, 5H), 3.90 (s,3H), 2.95 (s, 3H), 2.10 (s, 3H), 1.92 (s, 3H), 1.82 (s, 3H)-majordiasteromer (2.5/1); minor diastereomer shows the followingdifferences-1.99 (s, 3H), 1.76 (s, 3H) for --SCH₃ and --CH₃, the NH isis at 7.7 and the CH₂ region is 4.3-3.6 ppm.

The aqueous phase from the acid treatment can be neutralized andextracted with CH₂ Cl₂. The CH₂ Cl₂ solution can be dried, concentrated,and chromatographed on silica gel with 50% acetone/cyclohexane to give40% recovery of starting material (anilinoindoline) and 20% deacylatedstarting material.

The boranedimethylsulfide reductive elimination (on B) reaction isworked up by quenching with 1N HCl until gas evolution ceases and takingup in CH₂ Cl₂ /H₂ O. The separated organic phase is dried over Na₂ SO₄and concentrated. The residue is chromatographed on silica gel (50%acetone/cyclohexane) to afford 155 mg of product (9); 25% isolatedyield-85% based on recovered starting material), m.p. 182°-183° (phasechange at 160°, recrystallized from chloroform), the4,5-pyrrolo-6-methoxy indoline (9) (U-62,233).

NMR (CDCl₃): 8.3 (br. s, 1H), 6.96 (s, 2H), 4.2-3.5 (m, 5H+OH), 3.92 (s,3H), 2.87 (s, 3H), 2.41 (s, 3H).

Analysis: Calc for C₁₄ H₁₈ N₂ O₄ S: Calc: C, 54.17, H, 5.84, N, 9.03;Found: C, 53.49, H, 5.96, N, 9.42.

GC-MS: of O-acetate-m/e M⁺ 352 (13%), 213 (100%)-2'-1% SE-30,temperature 150°-260° (10°/minute); single peak.

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=>4, ID₉₀ (μg/ml)=>4

EXAMPLE 8 Preparation of the 4,5-pyrrolo-6-hydroxy indoline (10) fromthe 4,5-pyrrolo-6-methoxy indoline (9)

To 10 ml of dry, degassed HMPA (hexamethylphosphorictriamide) under N₂at room temperature is added 350 μl of butyl mercaptan. The solution iscooled in an ice-water bath and 2.0 ml of 1.5M n-BuLi in hexane is addeddropwise. After allowing the reaction to come to room temperature 100 mg(0.3 mmole) of the indole (9) is added with stirring. The solution isheated to 100° for 2.5 hours. The reaction is followed by tlc (50%acetone/cyclohexane) and when conversion appears approximately 75%complete (by vanillin/phosphoric acid spray), heating is terminated. Thecooled solution is poured into 1N HCl (100 ml) and extracted with 20 mlEtOAc. The separated organic phase is washed with additional 50 ml ofwater. The aqueous phases are combined and back-extracted with 20 ml ofEtOAc. The organic phases are then combined, dried over Na₂ SO₄,concentrated in vacuo, and applied to a 100 g silica gel column andeluted with 50 % acetone/cyclohexane. Afforded are 25 mg of startingmaterial and 45 mg of product (10) (44% isolated yield, 69% based onrecovered S.M.), the 4,5-pyrrolo-6-hydroxy indoline (U-62,370).

NMR (Acet-d₆): 7.8 (br. s, 1H), 7.03 (s, 1H), 6.83 (s, 1H), 4.25-3.25(m, 5H), 2.86 (s, 3H), 2.36 (s, 3H).

This product was treated with acetic anhydride (1.0 ml) and 20 mg ofNaOAc overnight, then taken up in CH₂ Cl₂ /H₂ O. The organic phase wasseparated, dried over Na₂ SO₄, and concentrated.

NMR (CDCl₃): 7.8 (br. s, 1H), 7.16 (s, 1H), 6.97 (s, 1H), 4.42, 4.20(dd, 2H), 4.2-3.7 (m, 3H), 2.86 (s, 3H), 2.40 (s, 3H), 2.35 (s, 3H),2.06 (s, 3H).

GC-MS: m/e M⁺ 380 (25%), 199 (100%)-2'-1% SE-30.

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=>5, ID₉₀ (μg/ml)=>5

EXAMPLE 9 Preparation of the 4,5-pyrrolo-6-hydroxy indoline bromide (11)from the 4,5-pyrrolo-6-hydroxy indoline alcohol (10)

To 25 mg (65 μmole) of the substrate alcohol in 1.0 ml of dryacetonitrile under N₂ at room temperature is added 33 mg (100 μmole) ofCBr₄ and 26 mg (100 μmole) of triphenyl phosphine (Ph₃ P). Afterstirring for 30 minutes an additional 11 mg CBr₄ and 8 mg of Ph₃ P areadded. The reaction is taken up in CH₂ Cl₂ /H₂ O after 60 minutes(total). The organic phase is separated, dried over Na₂ SO₄, andconcentrated. The residue is placed on three 20×20 cm 250μ silica gelplates and eluted with 50% acetone/cyclohexane. Approximately 8 mg ofthe higher R_(f) product (0.64; alcohol R_(f) =0.45) is recovered,compound (11), the 4,5-pyrrolo-6-hydroxy indoline bromide (U-62,694).

NMR (CDCl₃): 8.5 (br. s, 1H), 7.1 (s, 1H), 6.9 (s, 1H), 4.23 (d, 2H, J=6Hz), 4.0-3.5 (m, 3H), 2.89 (s, 3H), 2.38 (s, 3H).

Beilstein test: positive.

MS: Calc. for C₁₆ H₂₃ N₂ O₃ 79BrSSi=430.0382, Found 430.0375 (mono-TMS);m/e M⁺ 430/432 (14%), 271 (90%), 147 (100%).

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=0.12, ID₉₀ (μg/ml)-0.37.

EXAMPLE 10 Preparation of the 4,5-pyrrolo-6-hydroxy indoline mesylate(11) from the 4,5-pyrrolo-6-hydroxy indoline alcohol (10)

To 20 mg (65 μmole) of the alcohol substrate (10) in 1.0 ml pyridine inan ice bath with stirring under N₂ is added 8 μl of methanesulfonylchloride (70 μmole). After 30 minutes an additional 2 μl of CH₃ SO₂ Clis added and worked up with 2N HCl/CH₂ Cl₂ after 60 minutes totalreaction time. The organic phase is separated, dried over Na₂ SO₄, andconcentrated. Tlc indicates mostly lower R_(f) product (0.28 in 50%acetone/cyclohexane, alcohol R_(f) =0.46) and some higher R_(f) product(0.66). Preparative tlc (3-20×20 cm 250μ silica gel plates) affords 2 mgof higher R_(f) material (NMR indicated only one CH₃ SO₂ group; it isprobably the chloride) and 9 mg of the lower R_(f) material, compound(11) (U-62,695).

NMR (Acet-d₆): 8.6 (br. s, 1H), 6.97 (s, 1H), 6.74 (s, 1H), 4.3 (m, 2H),4.1-3.6 (m, 3H), 2.96 (s, 3H), 2.79 (s, 3H), 2.26 (s, 3H).

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=1.0, ID₉₀ (μg/ml)=3.3

EXAMPLE 11 Preparation of1,2,8,8a-cyclopropa[c]benzo[1,2-b:4,3-b']dipyrol-4(5H)-one (12),N-(methylsulfonyl)-

In following the procedure to prepare the 4,5-pyrrolo-6-hydroxy indolinebromide (step 10), if the reaction mixture prior to work-up isconcentrated in vacuo and applied to thick-layer silica gel platesdirectly, instead of isolating the higher R_(f) (0.64) product bromide,a new lower R_(f) band (0.32) is noted and recovered as compound (12).

NMR (CDCl₃): 9.5 (br. s, 1H), 6.83 (dd, H_(a)), 6.34 (s, H_(b)), 4.10(d, H_(c)), 3.93 (dd, H_(d)), 3.04 (s, 3H), 2.93 (m, H_(e)), 2.00 (d,3H), 1.97 (dd, H_(f)), 1.37 (dd, H_(g)).

J_(c),e =0.0 Hz, J_(e),g =4.4

J_(c),d =9.7, J_(f),g =4.4

J_(d),e =4.7, J_(NH),a =2.0

J_(e),f =7.7, J_(a),CH.sbsb.3 =<1.0

MS: silylation with BSTFA (DMF containing 1% TMS-Cl) gave m/e M⁺ 386/388(22, 12% corresponding to product+Me₃ SiCl).

UV: (methanol) λ224,272,338.

This compound was assayed by a standard tube dilution assay againstL1210 mouse leukemia cells in culture and gave the following results:

ID₅₀ (μg/ml)=0.13, ID₉₀ (μg/ml)=0.42

EXAMPLE 12 Alternate preparation of compound (12)

To the 4,5-pyrrolo-6-hydroxy indoline bromide (or mesylate) (0.1 mmole)in 1 ml of methylene chloride is added 0.1 mmole of diisopropylethylamine and stirred under N₂ for 24 hours at room temperature. Thereaction solution is taken up in 10 ml of methylene chloride, washedwith 0.1N HCl, dried over Na₂ SO₄, and concentrated to give the desiredproduct. Further purification can be accomplished by silica gelchromotography.

Compounds (11) and (12) exhibit antibacterial activity against B.subtilis, K. pneumonia, S. lutea, S. aureus and M. avium. ##STR1##

As used herein, alkyl of 1 to 2 or 1 to 5 carbon atoms, inclusive,includes methyl, ethyl, propyl, butyl and pentyl, and branched chainisomers thereof. ##STR2##

I claim:
 1. A compound of the formulawherein R₁ is selected from thegroup consisting of --CH₃, --CH₂ Ph, CH₂ ═CHCH₂ --, --CH₂ SCH₃, --CH₂OCH₃, --CH₂ OCH₂ CH₂ OCH₃, --CH₂ CCl₃, and --CH₂ CH₂ Si(R₂)₃ ; R₂ and R₃are hydrogen, alkyl of from 1 to 5 carbon atoms inclusive and phenyl;and X is selected from the group consisting of OSO₂ R₂, Cl, Br and Iwith the proviso that R₂ in the OSO₂ R₂ moiety is other than hydrogen.2. A compound having the formula ##STR3##